# Ratio

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#1
I cant get my head round this ratio question i think i have it but please can someone help :
To make get paint blank and white are mixed in the ratio 5:3.. How much black paint needed for
A) 10 litres
B) 12 litres
C) 21 litres i have got as far as in total there are 8 parts.... help please
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1 year ago
#2
So for 10 litres:
10litres divided by 8 parts which mean 1 part is worth 1.25l (10/8=1.25)
Therefore you need 5x1.25 of the first colour, and 3x1.25 of the second.
Repeat this for all amounts starting with dividing the parts by the amount of paint you need.
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#3
Awesome thankyou so I'm along the right lines with finding out 1 part then... It's there anyway that is a good resource to learn the ratio and proportion questions?
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#4
Sorry wasnt 10 It was 6 which i made 10 12 and 21...
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#5
So for 6 would be 8 dividee by 6 = 0.75 1part = 0.75 then 0.75 x 5 whixh is 3.75?
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1 year ago
#6
(Original post by Strach2k)
So for 6 would be 8 dividee by 6 = 0.75 1part = 0.75 then 0.75 x 5 whixh is 3.75?
For me the easiest method for this is to divide the part you want (the black paint) by the total ratio added up (8) and multiple this fraction by the given amount
e.g
For part a) you would do (5/8)*10
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#7
I don't get why you would x it by 10??
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1 year ago
#8
(Original post by Strach2k)
I don't get why you would x it by 10??
As you want to find how many parts of black paint there is OF 10 litres. So by doing 5/8 you find out how many parts of black paint there is in relation to the whole ratio and by multiplying by 10 gives you the amount on black parts in the whole 10 litres
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#9
Ahh ok cool so 5 /8 x 6 would give me 6 litres which is 3.75 yeah?
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#10
Can someone confirm this is right please.?
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